/*
 * Copyright 2020-2030 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.gitee.minimalismstyle.fresh.common.data.beetl.`fun`

import org.beetl.core.Context

/**
 * beetl自定义函数，将list<String> 转成拼接字符串
 * @author maoxiaodong
 */
class ListJoinFunction : org.beetl.core.Function {

    @Suppress("UNCHECKED_CAST")
    override fun call(paras: Array<out Any>, ctx: Context): Any? {
        return if (paras[0] is List<*>) {
            val list = paras[0] as List<String>
            if (list.isNotEmpty()) {
                var separator = ","//默认分隔符
                if (paras.size == 2) {
                    separator = paras[1] as String
                }
                list.joinToString(separator)
            } else {
                null
            }
        } else {
            null
        }

    }
}